We performed the complete screening of the CFTR gene in a group of 31 patients with COPD in order to investigate the impact of mutations and polymorphisms in the CFTR gene. The cumulative frequency of CFTR mutations (17.74%) was significantly higher than in our general population (P < 0.0001). The R75Q was significantly overrepresented in COPD patients (8.06%; P = 0.002). In all patients carrying the R75Q chronic bronchitis was a dominant symptom of COPD, and all were homozygous for the V470 allele. These findings suggest that R75Q mutation could be characteristic CFTR variant for COPD patients.

Imbalance between neutrophil elastase and alpha-1-antitrypsin (AAT) leads to emphysema in smokers as well as in patients with inherited alpha-1-antitrypsin deficiency. AAT as a proven inhibitor of apoptosis may play role in lung cancer (LC) progression. The aim was to analyse AAT protein variants and polymorphism in promoter region of the neutrophil elastase gene (ELA2) in patients with primary lung cancer. AAT phenotypisation by isoelectric focusing method and ELA2 gene promoter characterization by DNA sequencing were performed in 66 patients with primary lung cancer. Results showed that the frequency of M1 allele and PiM1 homozygotes in LC patients was significantly higher when compared to the healthy subjects (f  = 0.6360 and 0.7424 respectively). The most frequent ELA2 promoter region genotypes in LC patients were -903TT and -741GG. There were significantly more patients with intermediate and high ELA2 genotype activity, compared to those with low activity (91% vs. 9%, respectively). In conclusion, we found that PiM1 homozygosity could be associated with the lung cancer, probably due to increased synthesis of this antiapoptotic protein. Non-MM variants of AAT and ELA2 genotypes with predicted intermediate or high activity could also represent a risk factor for aggressive form of lung cancer associated with extrathoracic metastases.

Chronic obstructive pulmonary disease (COPD) is a complex disease influenced by genetic and environmental factors. Cystic fibrosis transmembrane conductance regulator (CFTR) protein is an important component of the lung tissue homeostasis, involved in the regulation of the rate of mucociliary clearance. As it is known that certain CFTR variants have consequences on the function of CFTR protein, the aim of this study was to examine the possible role of F508del, M470V, Tn locus, and R75Q variants in COPD development and modulation. Total number of 86 COPD patients and 102 control subjects were included in the study. Possible association between COPD susceptibility, severity, and onset of the disease and allele or genotype of four analyzed CFTR variants was examined. No associations were detected between COPD development, onset of the disease and tested CFTR alleles and genotypes. However, VV470 genotype was associated with mild/moderate COPD stages in comparison to severe/very severe ones (OR = 0.29, 95%CI = 0.11-0.80, p = 0.016). Our study showed that patients with VV470 genotype had a 3.4-fold decreased risk for the appearance of severe/very severe COPD symptoms, and the obtained results indicate that this genotype may have a protective role. These results also suggest the importance of studying CFTR gene as a modifier of this disease.

Chronic obstructive pulmonary disease (COPD) is a complex disorder influenced by multiple genetic and environmental factors, as well as their interactions. Since elevated oxidative stress and protease activity characterize the pathogenesis of COPD, variants of genes that can affect these processes have been commonly studied in COPD. However, interactions among genes that can influence oxidative stress and protease activity remain poorly investigated in COPD. The aim of this study was to look into the role of functional variants in matrix metalloproteinases (MMPs) 1, 9, and 12 in the occurrence and/or modulation of COPD, and to analyze their interactions with glutathione S-transferases (GSTs) M1, T1, and P1 in the pathogenesis of COPD in Serbians. The MMP1 rs1799750 G > GG, MMP9 rs3918242 C > T, and MMP12 rs2276109 A > G variants were analyzed by direct detection methods. Gene-gene interactions between variants in MMPs and GSTs were assessed using a case-control model. Our results showed association of the MMP1 GG/GG genotype with COPD (p = 0.036, OR = 2.50). Gene-gene interactions between the GSTM1 null and MMP1 GG (p = 0.028, OR = 2.99) and the GSTM1 null and MMP12 AA variants (p = 0.015, OR = 3.82) were found to significantly increase the risk of COPD occurrence. Furthermore, the MMP12 G variant was found to modify the age of COPD onset (p = 0.025, OR = 3.30), while interaction between the GSTM1 null and MMP9 T variants was found to modify the severity of disease (p = 0.019, OR = 4.83). To our best knowledge, this is the first study revealing several gene-gene interactions affecting oxidative stress and protease activity in the pathogenesis of COPD.